kern/94393: PseudoRAID loses track of the master disk

[John Giannandreaa]

>Number:         94393
>Category:       kern
>Synopsis:       PseudoRAID loses track of the master disk
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Mar 12 20:40:20 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     John Giannandreaa
>Release:        6.0 RELEASE i386
>Organization:
>Environment:
FreeBSD scapa.sv 6.0-RELEASE FreeBSD 6.0-RELEASE #4: Fri Nov 11 13:29:33 PST 200
>Description:
PseudoRAID on two ide disks, master on each channel.

reboot after atacontrol create raid

ar0: disk0 READY (master) using ad0
ar0: disk1 READY (mirror) using ad2

works wonderfully.   now lets power off ad0, and sync.

ata reports that ad0 is offline and raid is degraded.
ad2 hangs, reporting semaphore timeout !! DANGER Will Robinsion !

reset the machine.  boots correctly off ar0, with ad2 READY, ad0 not present.

halt, and reconnect ad0

now it boots with ar0 degraded as before, but finds ar1 also, with ad0 in it!
i.e. it sees two mirros with one disk each.  ar0 is thankfully the correct one.

atacontrol delete ar1, reboot.

back to having only ar0 degraded, with ad2 as master.  so far so good.

BUT cannot add ad0 back in to the raid, reports "busy".

what you can do, apparently, is atacontrol addspare ar0 ad2
and then do a raid rebuild.

It seems as though the PseudoRAID has lost track that ad2 became master
and that ad0 is the mirror now and has inverted them.


>How-To-Repeat:
see description

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: